This is what you'll need to have to hand...

250 g unsalted butter (melted)
125 g white granulated sugar
125 g light muscovado sugar
3 medium-sized eggs
1 tsp vanilla bean paste
300g plain flour
1 tbsp cornflour
200 g white chocolate chunks
250 g Biscoff spread
100 g Biscoff biscuits

1. Melt the butter in a pan over a medium heat.
2. Add the sugars into the melted butter and beat together until it is smooth.
3. Add the eggs and vanilla paste and beat again, until smooth.
4. Sieve in the flour and cornflour, then beat until you have a fudgy brownie sort of texture.
5. Fold through the white chocolate chunks then pour the mix into a lined and greased tray.
6. Dollop the biscoff spread over the top and then use a fork to lightly swirl it through.
7. Crumble the biscuits into different sizes and sprinkle over.
8. Bake in the oven at 165℃ for 30 minutes. Check it at 25 minutes, it should have a slight wobble in the middle.
9. Cool completely before cutting into portions and enjoying!